sendmail problem

recently i started using an exchange hosting company to host my email and i changed my MX records so that email to [email protected] goes to their server. everything is working fine except for email sent from my web server (www.mydomain.com).

specifically... i have a contact page (www.mydomain.com/contact.html) on my website that uses a php script to send email to [email protected]. it worked just fine before i started using the exchange host. actually the script still sends a message to the local 'info' account.

in sendmail i added '[email protected]' as an alias to the local 'info' user but this has not made any difference.

i think the problem is that somehow the web server has no idea that the exchange server exists -- even though the MX records point to it.

thank you. i have done exactly as you suggested but it hasn't solved the problem. it just seems strange that sendmail isn't looking to the MX record for the domain - if it did it would know where to send it.